When, for example, a video signal processing apparatus such as a scan converter displays a video output from a video output apparatus such as a personal computer (PC) and a video camera on a screen of a display apparatus such as a monitor, the video signal processing apparatus is connected between the video output apparatus and the display apparatus. The video signal processing apparatus converts a frequency of a signal (video signal) from the video output apparatus at the input side in accordance with the display apparatus at the output side, and outputs the converted signal to the display apparatus. The video signal processing apparatus includes an input terminal to which the video signal from the video output apparatus is input and an output terminal from which a processing signal provided by processing the video signal is output.
Some video signal processing apparatuses synchronize a signal from the video output apparatus with a synchronization signal and output it to the display apparatus. These video signal processing apparatuses include a synchronization signal input terminal to which the synchronization signal from a synchronization signal generation apparatus is input. That is, the video signal processing apparatuses include the synchronization signal input terminal in addition to the two types of terminals of the input terminal and the output terminal. In other words, the video signal processing apparatuses need to have areas in which the three types of terminals are disposed. Thus, reduction of the video signal processing apparatuses in size is restricted by the number of terminals.
Techniques have been proposed to reduce the apparatus in size by causing one terminal to also have functions of different terminals (for example, refer to Japanese Unexamined Patent Application Publication No. 2002-94982).